1. Field of the Invention
This invention relates to vehicular automatic or partially automatic mechanical transmission systems and, in particular, to control systems/methods for vehicular fully or partially automated mechanical transmission systems for sensing driveline torque phase, magnitude and/or changes in driveline torque magnitude for control of the transmission system without the use of driveline torque transducers.
More particularly, the preferred embodiment of the present invention relates to an automated mechanical transmission control system/method which enhances shift decisions and/or shift implementation by monitoring the value of parameters indicative of input shaft speed (IS), output shaft speed (OS) and engaged gear ratio (GR) to determine values indicative of driveline torque phase and/or magnitude of driveline torque and/or change in magnitude of driveline torque.
2. Description of the Prior Art
Fully automatic transmission systems (both for heavy-duty vehicles, such as heavy-duty tracks, and for automobiles) that sense throttle openings or positions, vehicle speeds, engine speeds, transmission shaft speeds and the like, and automatically shift the vehicle transmission in accordance therewith, are well known in the prior art. Such fully automatic change gear transmission systems include automated transmissions wherein pressurized fluid is utilized to frictionally engage one or more members to other members or to a ground to achieve a selected gear ratio, as well as automated mechanical transmissions utilizing electronic and/or pneumatic logic and actuators to engage and disengage mechanical (i.e., positive) clutches to achieve a desired gear ratio. Examples of such transmissions may be seen by reference to U.S. Pat. Nos. 3,961,546; 4,081,065 and 4,361,060, the disclosures of which are hereby incorporated by reference.
Semi-automatic transmission systems utilizing electronic control units which sense throttle position, engine, input shaft, output shaft and/or vehicle speed, and utilize automatically controlled fuel throttle devices, gear shifting devices and/or master clutch operating devices to substantially fully automatically implement operator manually selected transmission ratio changes are known in the prior art. Examples of such semi-automatic transmission systems may be seen by reference to U.S. Pat. Nos. 4,425,6270; 4,631,679 and 4,648,290, the disclosures of which are incorporated herein b reference.
Semi-automatic shift implementation systems/methods for mechanical transmission systems for use in vehicles having a manually only controlled engine throttle means and/or a manually only controlled master clutch also have been proposed. Such systems may be seen by reference to U.S. Pat. Nos. 5,053,959; 5,053,961; 5,053,962; 5,063,511; 5,050,079; 5,081,588; 5,089,962 and 5,105,357, the disclosures of which are incorporated herein by reference.
The automated shift selection and/or shift implementation of the above-mentioned fully or partially automated transmission systems may be enhanced if information relative to driveline torque phase and/or magnitude is available, preferably without the additional complication and expense associated with providing a driveline torque transducer or the like.